Slip assembly



Abril 11, 1939. ON 2,153,770

SLIP ASSEMBLY Filed July 9, 1936 2 Sheets-Sheet l 5 a w -|||||||.m

' l7 48 2| [5 wily;

' Jeddlj D. Nikon, 22 Q $12.2

as, I r 1 April 11, 1939. NIXON "2,153,770

SLIP ASSEMBLY Filed July 9, 1936 2 SheetsSheet .2

Patented Apr. 11, 19 39 UNITED ST TES aisa'm' sun ASSEMBLY ZleddyD.Nixon, Houston, Tex, assignor, ii, mesnc' Company ents, of fifty percent to Wilson Supply v Application July 9, 1936, Serial No. 89,842

=With the ordinary slips now in common use,

one of the main disadvantages-is that the slips stick in the bowl or thebushing or head, and in order to be'loosened therefrom, the slips haveto be hammered or knocked loose. One of the reasons the slips stick inthe bowl-is that the transverse arc and inclination of the. back of eachslip and the are and inclination of the bowl do not register, as the arcof the bowl is struck on a' greater-radius than the arc of the slip. It

- is pointed out that the slips have only a minor portion of theirarcuate surface-contacting the bowl, and therefore, due to the excessiveweight of the spring of pipe supported by the slips, the

' small bearing surfaces of the slips on the bowl will have a tendencyto freeze or stick the slips.

In addition, an excessive amount of wear occurs,

so that in a relatively short time the back of the slips are so worn asto impair their emciency As. this wearing continues, the freezing orstick- 4 ing of the slips in the bowl is accentuated. when the point isreached where the inclination of the back of the slips and of the bowl,actually match or correspond, and the transverse are of the back of theslips and that of the bowl register, then the slips cease to hold. Anexcessive amount of forcing or hammering is required to make the slipshold,'because with the inclination ,and'arc of. the slips and bowlregistering, the binding and gripping action pf the slips isreduced tosuch. e an extent that to obtain a gripping ofthe slips the same has tobe forced or hammered; which has the usual detrimental results ofbattering,

damaging and breaking the slips, whereby their life is materiallyshortened and their period of usefulness'reduced,

One object of the luv improved slip assembly, soconstructedthat theslips may be'readily inserted into the bowl to gripa pipe in the well,or withdrawn to release said pipe. I

Another object of the invention is to provide a slip assembly sodesigned'that the slips will not stick in the bowl and may be easilywithdrawn; was to releasethe pipe. i

Still another'object of the invention is to pro vide an improved slipassembly having an angular tapered or inclined bowl, the slips beingsoconstructed as to conform to theangularities of said bowl, whereby themanual removal of the slips from saidbowl may be readily accomplished,

and the use of a tool, such as a hammer or the like, is not required.

ntion' is to provide an A further object of the invention is to providea slip assembly having a'slip so constructed with a flat surface on itsback, so as to conform to the flat surfacesof the bowl of the bushing,whereby the complementary angularities of the back of J 5 the slips andof the bowl, provide a positive gripping of the pipe at all times.

Another object of .the invention isto provide an improved slipassemblyhaving' amplified contacting surfaces so that the-slip has afull and true bearing surface with the bowl and a complete contactbetween said bowl and slip is obtained, whereby the life and period ofusefulness of the slip and bowl are materially'increased.

- A construction designed to carry out the invention will be hereinafterdescribed, together with other features of the invention.

The invention will be more readily understood from a reading of thefollowing specification and by reference tothe accompanyingdrawings, in20 which an example of the invention is shown, and wherein:

Figure 1 is an isometrical view of a slip assembly constructed inaccordance with the invention, and a pipe being gripped by the slips,

"Figure 2 is a similar view of a slip assembly mounted on a casing headand showing the slips removed from the bowl, 1

Figure 3 is a plan-view of the bushing,

' Figure 4 is a transverse vertical sectional view taken on the line of4-4 of Figure 3,

Figure 5 is an isometrical view of without the handles,

Figure 6 is a plan view of the slips as shown in Figure 5, V V

' Figure 7 is an elevation of one of the slips, showing the grippingsurface,

Figure 8 is a vertical sectional view taken 'on the line 8-8 of Figure'7 Figure 9 is a plan view of the handles,

. Figure 10 is a transverse vertical sectional view taken on the lineIll-Ill of Figure 9, and

Figure ll is a vertical sectional view taken on thelinell-ll ofFlgure3.

In the drawings the numeral l5 designates an annular bushing, adaptorring, or headiormed preferably 'of two semicircular sections. Thesesections are hinged together by a hinge it, comprising two laterallyprojecting ears [1 on. onesection and a horizontally extending tongue l80n the other section projecting between said ears.

A pintle I6 is passed through the ears and the tongue, so as to hingethe same together. Diametrically opposite the hinge, the sections arelatched together by a somewhat similar arrangement to the hinge I3,including a lock pin it extending through a pair of laterally projectingears 2| on one section and a horizontally extending tongue 3I on theother section. Thus, by swinging the sections together on the hinge I3and inserting the lock pin I9 the sections are latched together and toopen the adaptor the above operation is reversed. The lock pin I3 isprovided with an angular fiat head 40 which is countersunk in the top ofthe adaptor and has a portion disposed in a short, shallow channel 20,which extends from the countersink to the periphery of the adaptor andis a little deeper, than the countersink, in order that a pointedinstrument may be inserted under the head of the bolt I9, to lift thesame. The bottom of the adaptor is substantially flat, so that it may bereadily seated or placed on a casing head 22 (Figure 2), or if desired,on a rotary. table or other suitable support.

The adaptor is provided axially with an inclined or wedged shapedopening 23 preferably extending therethrough, which is angular in plan(Figure 3). For the purpose of illustration, the opening 23 has beenshown and described as in the form of a square, but it is to be clearlyunderstood that said opening may be triangular or any suitable polygonalshape desired. The opening. .23 is provided with fiat, smooth, upwardlyinclined sides or faces 24 (Figures 3 and 4) which converge downwardly.It will be seen that the egree of inclination of the bowl is somewhatsmaller than ordinarily occurs in the bowl of usual adaptors, butwithout the usual detrimental results. In the usualslip and bowl now incommon use, when the degree of inclination is, increased the slips failto hold the pipe, and when the degree of inclination is decreased theslips stick in the bowl and have to be knocked loose. 40 In Figures 3and 4, it will be noticed that the inclination or pitch of the bowl.is'relatively steep,

but the slips will grip the pipe and will not stick in the bowl,regardless of the length of use or amount of wear.

When the slips 2! are placed together, as shown in Figures 5 and 6, itwill be seen that their per portion is circular and that their lowerportion is formed to conform to the faces 24 of the bowl 23. As will beseen in Figures 1, 2, 5 and 8, the slips are'provided with a. large,fiat. bearing surface 23 on their backs for engaging the faces 24. It'is pointed out that the large, flat bearing surfaces 23 of the slips 25engaging the faces 24, provide an ample support and guide for the slips.When an oil or lubricant is placed on the faces 24 of the bowl 23, thefiat bearing. v surfaces of the slips will not destroy the film oflubricant on the faces ,24, as would occur if a small bearing surfacewere presented, such as "Q happens with the slips now in common Thelower portion I26 of each edge of each slip is inclined on a downwardlyreducing taper, so that when the slip segments are fitted into the slipbowl, the two lower corners of eachslip will not 55 contact norinterfere with the proper functioning ofany oi the other slips. Thefaces I23 and the edges of the slips will fit into the enlargements orspaces I21 provided in the opening 23 of the bowl between each face 24,whereby the segments 70 will not interfere with each other and theopening 23 does not need to be as large as otherwise woi'id be needed. 7

In the drawings, the slips are illustrated as being made into the samenumber of sections as 6 there are faces-provided in the bowl 23 of thebushing I5, which in this instance is four sections, though it is to beunderstood that the slips may be so constructed that two flat bearingsurfaces may be provided on each of the slips, whereby only a half ofthe number of slips are used inaccordance with the number of faces ofthe bowl presented. As will be seen in Figures and 6, these sectionswhen placed together are provided with an axial, circular openingextending therethrough. The inner face of these slips is provided withteeth or serrations 21 for gripping the pipe or tubing .28 extendingthrough the slips and down-into the casing 29 of the well.

In Figures 1, 2, and 9 are shown slip handles 33 which may be used withthe slips. These handles are provided internally with an annular boss32, so that when the handles are placed around the slips, said boss willmesh with an annular circumferential groove 30 provided in the upper endof the slips. The handles and boss 32 are drilled or provided with boltopenings 34, one for each slip, and suitable bolt 3| may be insertedthrough the opening and threaded into an internally screw-threadedopening 3.5in the periphery of each slip. The bolt openings 34 are madea little larger than the bolt .3I to be inserted therethrough, in orderto permit a small amount of movement of said bolt in said openings.Thus, it will be seen that the bolt will draw the slips onto the bossand it is preferable that the slips are not drawn tight, but a verysmall space or amount of play is left between the slips and the boss 32,whereby a certain amount of play or movement of the slips is had. Theto!) of each slip is provided with an internally screwthreaded opening36 into which-is inserted a short screw 31, preferably provided with abronze plug (not shown) on its lower end, so as to engage the threads ofthe bolt 3| and lock the same in the opening 35.

The slip handles 33 are made into two sections and are hinged togetherat 33. The handles may be suitably latched together. A dowel pin 42 on 7one of the sections'of the slip handles co-acts with a'port ,or' hole 44in the other section, so as to facilitate the aligning of the sectionsin order that they may be readily latched together. The slip handles areprovided with hand holds 43 and 41 on each end, so as to swing and liftthe slip handles, as desired.

Attention is called to the fact that it is possible to make the slipswith two or more flat surfaces on their backs so as to fit and co-actwith two or more of the fiat sides of the bowljof said head I5, withoutdeparting from the spirit of the invention Thus, it will be .seen thatthe number of slips could be reduced, in accordance with the numberof'fiat faces in the bowl 23. Various modifications of the invention arepossible.

In operation, the sections of the head or bushing I5 are swung togetherand placed above or on a casing head 22, (Figure 2) a rotary table, (notshown) or any other suitable support, as desired. When the two sectionsof the head I5 are swung together, the lock pin I3 is inserted so as tolock the two sections together, as is the usual practice. The fiatbottom of the head I 5 permits the ready placing or installation of thehead upon any suitable surface or support. The head is now ready toreceive the slips 'Aswillbeseen in Figures 1 and 2, theslips are mountedon the slip handles 33 by means of the boss 32 fitting within theannular groove on the upper end of the slips 25, and the bolts 3|extending through the bolt holes 34 to fasten the e, never'meet orcontacts the threads of the bolt 3i, so as to fasten 5 the same in saidbolt, holes ll.

In making up a string of tubing 2!, the slips 2! are engaged around theupper end of the string of tubing suspended through the bowl of the headis, the tubingandslip are lowered and the flat the slips engaging thebearing surfaces 2 of. faces 24 of the bowl 2!, will force the slipsinto rinnin engagement with the tubing. An additional joint of tubing isthen screwed onto the upper end of the string, and-said string is ele-.with. said string. when the slips are sufficiently above the. head It,a workman may open the same by gripping the handles 1 and swinging themapart.

The slip assembly. may be placed upon. the upper vface of the' head It,as shown in Figure 2, and the lower end of the slips being at rightangles to. each other,will form a brace or supportforsaidslip assembly.with the slips placed uponthe head II. 25 it will be seen that the slipassembly is in a very soastobeinreadinessto convenient position, beagain applied to the tubing. The entire string is then lowered until itsupper end is opposite the tubing slips 25, and' the workman may thengrip the handles ll and 48 and seat the slips 2! ing position aroundsaid ,tubing 18, as above described. Thus, it will be seen that saidstring of tubing is completed, asis the usuaPpractIce, by repeating-thisoperation. 7 g In breaking out a string of tubing, the upper ioint tobeunscrewed extends above the tubing orcasing head 22 with the slips 2!-engaging the string 'of tubing beneath the joint. When the voted,carrying the, slip assembly upwardly with :it until. they clear theupper end of the head It. and thenthe slip assembly is removed fromaround the-tubing as has been described. Again the slipiassemblyfisplaced upon the top of, the head-l5, as shown in 'Figure'2, where it isin readiness to-be used .again. .continued until the This, wlllbeseen-that tho broad, flat bearing surfaces 2. of the slips II engagingthe facesll suns whole as long as thet'eeth iiwiu the tubing 28, becausethe inclination oithe back of tie-sup. andtl'i'einclinationofthebowlwill onthemcannotbeobtainedvated, whereby the, slips are carriedupwardly of the slip assembly in the bowl I! in tubing holdof the fiatfaces of the opening without contact joint is unscrewed-and removed, thestring is elelarly disposed and engagin the-flat faces of the Thisoperation is V string is completely, broken out or made up, whicheveroperationis in prog-' cross-section and having enlarged spaces at the 5corners of said opening to provide outstanding inclined flat faces, andarcuate slips fitting-in said head opening and having inclined flat backfaces engaging the flat races or the opening.

2. A slip assembly including, a headhaving a vertical tapered openingtherein or p l gonal cross-section and having enlarged spaces at thecorners of said opening to provide outstanding continuous inclined broadflat faces free from projections and 'cuate slips fitting in said headopening and he ng continuous inclined broad flat back faces free fromwedges engaging the flat faces of the opening.

I '3. An arcuate slip member of the type-having arcuate gripping teethon its inner surface pro- 'vided with aflat inclined face onthelowerportion or each edge thereof, and having a flat outer 'surfaceinclinedtoward one end. whereby a bearing surface is provided slip bowl.

i. A slip assembly including, a head having a vertical tapered openingtherein of polygonal cross section and having outstanding inclined flatfaces and spaces between the'upright edges of the faces, and arcuateslips fitting in said head opening and having inclined flat back. facesengaging the flat faces of the opening, the upright intersectionsbetweenthe flat'f'aces of the slips standing in the spaces betweentheupright edges for engagement with. a

with the-head, whereby the flat faces of the slips are free to-nrmlycontact the flat faces of. the opening without limitation by the uprightedges 1 of said slips.

5. A slip aissemb vertical opening t erein provided with an u ar sideshaving fiat faces with their upright edges spaced apart, and'slipsfitting in said head openins and having inclined fiat back facesanguincludingt a head having a angular sides of the opening,'-'theupright intersections between the flat iaces of-the slips stand,-

ing in the sp'acesbetweenthe upright edsesof the faces of the openingwithout contact with the head, whereby the flat faces of the slips arefree to iirmly contact the-faces ofthe opening A W thout limitation byth upfll t Q1898 of said slips, the lower end of each slip section beingreduced and the maior portion of eachsiip being arcuate,'said arcuateportion partially surroundinclinedilat siipiaoe extending fromtiie'arcuate and! nmon.

. ts ling the upperportion ofthe flat slip fslce, the

